According to Mac rumor site the Unofficial Apple Weblog, Apple seems to be poised to release the successor to its Leopard operating system, aka OS 10.5, at its World Wide Developer Conference later this month. The update to 10.6 will reportedly be called “Snow Leopard,” as it will mainly be a revision and improvement on the current 10.5 release, with few totally new features. Those improvements run the gamut from “security and stability” to speed and performance, as well as another salient change: lack of support for Apple’s old PowerPC chips (the G3, G4 and G5.) If Snow Leopard is indeed a clean, 64-bit Intel-only OS, it could mark the end of the once-controversial chip transition, and the end of the development of Universal applications. That probably won’t be a welcome change to a lot of legacy Mac users, but then, Apple has always marched to the beat of its own drum — not to that of focus groups.

Also in Mac-land are a handful of rumors about the next-generation iPhone, which will reportedly add true GPS and 3G speeds to an otherwise-unchanging revision. The new iteration will reportedly be available for the first time in Japan, on the carrier Softbank, leading many analysts to wonder if there’s any market for the Western genius phone in a typically domestic-gadget-loving country like Japan. Whispers about the phone’s new enclosure have also been revived, with some blogs resurrecting earlier-discredited leaks which report that the new iPhone will be slighty thicker in size, glossy black on the backside, with squared bezel edges and less chrome trim along the face.